Buffer mechanism.



W. W. PERKINS.

BUFFER MECHANISM.

APPLICATION FILED OOT. 2-1, 1907.

Patented Nov. 3, 1908 2 SHEETS-SHEET 1.

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W. W. PERKINS. BUFFER MEGHANISM.

APPLIUATION FILED OUT. 21, 1907. 902,601 Patented Nov. 3, 1908.

2 SHEETS-SHEET 2.

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UNETE 51 WARREN W. PERKINS, OF NORWOOD.

OHIO.

BUFFER IVIE CHANISTE.

Specification of Letters Patent.

Application filed October 21, 1907.

Patented Nov. 3, 1908.

Serial No. 398,434.

To all whom it may concern:

Be it known that I, /VARREN 1V. Perkins, a citizen of the United States, residing at Norwood, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Buffer Mechanism, of which the following 1s a specificabe arrested with an easy motion for avoiding jar to the parts.

Figure 1 shows a front elevation of a gage lathe embodying my invention. Fig. 2 is a rear elevation of the same. Fig. 3 is a front elevation of the cushioning part showing the same in connected relation. Fig. i is a similar view showing the cushioning chamber in longitudinal section on a line corresponding to the line a2-a9 of Fig. 5, showing the parts 111 collapsed relatlon in full lines and in distended relation in dotted lines. Fig. is a cross section on a line corresponding to the line -y of Fig. 4:, and, Fig. 6 is a detail of the carriage on the line 2 2 of Fig. 1.

In machines of the character to which my invention is principally applicable there is usually a feed-screw employed for causing the advance or cutting travel of the carriage, at the end of which movement the engagement between the nut on the carriage an the feed-screw is released for permitting the carriage to return quickly to initial position under pulling stress of a weight suitably connected with the carriage.

In gage lathes as heretofore constructed, it has been found necessary by the operator to manually retard the return of the carriage by pressing his hand against the same for holding it against the pull of the weight in order to ease the jar at the end of the return of the carriage, the being occasioned by the striking of the carriage against the tail-stock or other part provided 11 the lathe for limiting its return. This employment of the hand was a tiring operation and interfered with the proper handling of material and rapid operation of the lathe, as it consumed moments of time which could be better employed in the manipulation of material or operating parts of the lathe. While this manual retarding of the carriage aided somewhat in relieving the jar, it has been found in practice that sufiicient pressure could not be exerted to overcome the jar while employing a weight or other return agency which would return the carriage to initial position with sufficient rapidity for practical operation. I obviate these diiiiculties by providing means whereby the carriage may be returned to initial position with great rapidity. During the final portion of the return movement of the carriage 1 subject it to a counter pressure, preferably an air pressure, which quickly slackens the speed of return movement of the carriage and causes it to come to rest with an easy motion, and in practice relieving the stoppage of the carriage of jar and relieving the operator of the duty of attention to the stoppage of the carriage on its return movement, thereby permitting the operator to give his attention to the manipulation of the material and the advance travel of the carriage for cutting the mate rial, with the result that the life of the machine is lengthened and its capacity enhanced. My improved device enables me to employ a quicker return.

1 represents the bed of the lathe and 2 is the carriage which travels longitudinally of the bed on ways 3, the carriage extending across the top of the bed in usual manner.

4L is the head-stock in which a suitable head-spindle 5 is journaled and rotated in suitable manner.

6 is the tail-stock which carries a usual tail-spindle 7, the material or stock 8 being supported and rotated between the spindles.

10 is a feed-screw journaled in suitable bearings 11 and operated in suitable manner.

12 are ordinary half-nuts movement in the apron 13 of the carriage and having pivotal connection, as at 14, with a double-throw lever 15 secured to rock-shaft 16 having a lever 17 thereon. In the construction shown, when the lever 17 is swung downwardly, the half-nuts are released from the feed-screw, and when the said lever is swung upwardly said half-nuts are connected with the feed-screw.

18 is an operating lever pivoted at 19 to the carriage and having an arm 20 provided with a bolt 21 movable in a slot 22 of a link 23 pivoted at 24 to the lever 17.

25 is a depending arm swinging on a pivot mount ed for 26 on the carriage. This arm has a lug 27 thereon adapted to have engagement made therewith by a lug 28 on the lever 17, a sprin 29 secured to the arm and lever 17 normally urging the lug 27 into the path of travel of the lug 28. The arm 25 also has a lug thereon upon which the lever 17 may rest when the half-nuts are disengaged, these half-nuts being engaged with the feedscrew when the lugs 27 28 are in engage ment.

31 is a tappet which is adjustable along the bed, the arm being adapted to strike the tappet for causing the lug 28 to be pushed. out of range of the lug 27 and thereby causing the lever 17 to swing downwardly for opening the half-nuts and releasing the car riage, the moment of release being determined by the position of the tappet lengthwise of the bed. As soon as the carriage released it is brought under the influence of a returning agency shown as a weight 32 attached to a belt secured to the carriage at 34 and passing over a pulley 35 on the bed and over suitable pulleys 36 37.

The carriage has a gage-knife or cutting tool 40 secured in a gageknife support 41 pivoted on a stud t2 on the carriage, the support having a finger 13 which engages'a gage-plate 'hlsuitably secured to the bed and formed with a contour according to the shape it is desired to give the material being turned. gage-knife supports. If desired the cutting of these tools may be supplemented by a back-knife 15 adjustably secured to a back knife slide 46 movable up and down in ways 47 of an upright frame 48 secured to the bed, the backknife slide being caused to move up and down by having a diagonal slide-way 4L9 thereon with which a guideblock 50 on the carriage engages. In order to prevent binding of the slide in the upright frame and to counter-balance the same, the slide is at each end provided with a rack 51 with which pinions 52 engage, the pinions being on a shaft 53 journaled in bearings 54 of the upright frame and having counterpoise sheaves 55 56 secured thereto, straps 57 58 having one of their ends secured to said respective sheaves and being provided with suitable weights for counterbalancing the upright frame.

61 is a chamber shown as a which a piston 62 is adapted to reciprocate. A piston-rod 63 is secured to the piston and is guided in a bearing (a of the head 65 of the chamber. The piston-rod is preferably prevented from turning, :for accomplishing which I have shown the piston-rod with its bearing as of rectangular cross-section.

The piston-rod has an arm 66 pivoted thereto as through the medium of a yoke 67 secured to the pistonrod and carrying the pivot 68. The arm has a hook G9 thereon cylinder in There may be one or more of these adapted to engage with a keeper 70 on the carriage, this keeper being shown on a plate Tl secured to the carriage.

72 is an inclined way shown on a lug 73 on the chamber, the inclined way being adapted to be engaged by the arm 66 in rear of its pivot for causing disengagement between the hook and keeper. I have shown the rear end of the arm 66 provided with an anti-friction roll 74: adapted to ride on the inclined way, the arm being provided with an upward bow T5 for clearing the lug 73. The outer end of the piston-rod is adapted to be received by a recess 76 in the plate 71, the recess preferably having a tapered wall 77 for centering the piston-rod.

\Vhen the carriage is at the beginning of ts advance travel or cutting movement, the hook and keeper are in engagement. W hen carriage begins to travel in its cutting movement under the influence of the feedserew, the piston-rod, being engaged with the carriage, is moved with the carriage for drawing out the piston-rod, the roll 74 riding on top of the chamber. This movement continues until the roll 7 1 has traveled upwardly on the incline 72 as shown in dotted lines in Fig. 1-, thereby disengaging the hook and keeper and releasing the engagement between the piston-rod and carriage, the carriage continuing its travel disengaged from the piston-rod. hen the cutting n'ioveinent has been accomplished and the half-nuts released from the feed-screw, the carriage is quickly returned to initial position under the influence of the weight 82, the carriage. through the plate 71 thereon, striking the end of the piston-rod and compressing the air to rear of the piston in the chamber which forms a cushion for the carriage. The cushion is released by providing the chamber with a suitable opening communicating therewith, which I accomplish through the stop-cock 78, through which the rapidity of release of the cushion may be regulated, thereby bringing the carriage to an stop and providing a cushion for preventing jar upon the return of the carriage. I also preferably provide the forward end of the chamber with suitable openings 79 80, the opening SObeing preferably in rear of the piston, but closely adjacent thereto for relieving suction upon the piston when it is withdrawn to its limit.

Having thus fully described my invention what I claim as new and desire to secure by Letters Patent is:

1. In buffer mechanism, the combination, with a bed, a carriage movable longitudinally thereon, means for advancing said carriage, and means for causing quick return of said carriage, of a cushion for said carriage for cushioning said return com prising a chamber-member and a pistonmember therefor, and means connecting with one of said members for distending said members by the movement of said car riage, one of said members provided with an inclined way acting on said last-named means for releasing said connection.

2. In bufler mechanism, the combination, with a bed, a carriage movable longitudinally thereon, means for advancing said carriage, and means for causing quick return of said carriage, of a cushion for said carriage for cushioning said return comarising a chamber-member and a pistonmember therefor, a regulating valve for said chamber-member, and means connecting with one of said members for distending said members by the movement of said carriage, one of said members provided with an inclined way acting on said last-named means for releasing said connection.

3. In buffer mechanism, the combination, with a bed, a carriage movable longitudinally thereon, means for advancing said carriage, and means for causing return of said carriage with a quick movement, of cushioning means for said carriage for cushioning said return comprising a chambermember and a piston-member therefor, releasable connecting means for one of said members for distending said members upon advance of said carriage, said connecting means comprising a hook and a keeper therefor, and a lever on which one of said last-named parts is mounted, said lever pivoted to said piston-member, and said chamber-member having a lug thereon upon which said lever rides for releasing engagement between said hook and keeper between the ends of advance movement of said carriage.

f. In buffer mechanism, the combination of a cushion-member, a piston therefor, a piston-rod secured to said piston, a lever pivoted to said piston-rod, connecting means between said lever and a pulling part, said lev r having a rearward extension and said chamber having an inclined way thereon with which said extension is arranged to contact for releasing the connection between said lever and pulling part, ubstantially as described.

in buffer mechanism, the combination a cushion-chamber, a piston therein, a n ton-rod for said piston, a lever pivoted to id piston-rod, a pulling part, said pullingpart and piston-rod having a recess between em for relatively positioning the same, releasable connecting means between said lever and pulling-part operative during ini tial pulling movement of said pulling-part, and means for causing release in said connecting means upon further pulling movement of said pulling-part, substantially as described.

6. In buffer mechanism, the combination of a cushion-chamber, a piston having movement therein, a piston-rod therefor, a catch on said piston-rod, means for releasing said catch, said chamber having openings in advance of said piston and a regulating valve for said chamber to rear of said piston, substantially as described.

in testimony whereof I have subscribed my name hereto in the presence of two sub- .-:cribing witnesses.

VAR-HEN N. PEREHNS. Witnesses J. BENJ. Marlins,

FLORENCE QUINN. 

